The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingRemoval
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove front fender liner lh
Remove front fender liner lh
Remove the ...
Turn signal light circuit
Description
The turn signal flasher relay (marking: flsh) in the main body ecu turns on
when it receives signals
from the headlight dimmer switch integrated with the turn signal switch, causing
the turn signal lights to
flash.
Wiring diagram
Inspection procedure
Check operation of t ...
Removal
Hint:
Use the same procedures for the rh side and lh side.
The procedures listed below are for the lh side.
Remove front pillar cover sub-assembly upper lh
Using a moulding remover, detach the 3 clips and
remove the pillar cover.
...